Localization and therapy system for treatment of spatially oriented focal disease

ABSTRACT

A transducer assembly for visualization and treatment of transcutaneous and intraoperative sites includes in combination a visualization transducer and a treatment transducer, each of which are movable with both linear and rotary degrees of freedom. Movement of each transducer is by various motor and geared drive arrangements wherein certain degrees of freedom for one transducer are separate and independent from the degrees of freedom for the other transducer. At least one degree of freedom for each transducer is common and the transducers are moved concurrently. 
     One arrangement of the transducer combination is for prostate treatment and includes a specific shape and configuration for anatomical considerations and a control unit which is operable external to the patient to control both transducers and a reflective scanner which are inserted into the patient as part of the ultrasound probe.

BACKGROUND OF THE INVENTION

The present invention relates in general to the treatment of disease,tumors, etc., by the use of ultrasound. More particularly the presentinvention relates to a combined visualization and treatment device usingultrasound for both functions. Treatment is achieved by ablation oftissue representing the disease entity.

A large number of diseases manifest themselves in whole or in part in afocal manner. These include, for example, diseases of or in the brain,breast, liver and prostate. While surgical procedures have traditionallybeen employed when medicinal approaches were not suitable or effective,surgery still represents a significant risk to the patient and a chancethat the entirety of the disease entity will not be completely removed.

There is no dispute as to the value of noninvasive treatment as such asproducing volume lesions with focused ultrasound. One difficulty thoughwith ultrasound treatment procedures is the need to visualize thedisease entity and thereby determine the size, shape and location. Whilethis concern does not normally exist with invasive techniques such assurgery, it is of critical concern in noninvasive procedures.

In our pending application entitled ULTRASOUND BRAIN LESIONING SYSTEM,Serial No. 163,260, March 2, 1988 filed on even date herewith, avisualization technique is described for volume lesioning treatment of abrain tumor. The technique involves a use of ultrasound or CT or MRIscan transparencies whose data is digitized into a computer and landmarkreferences from a skull fixation apparatus are used to preprogram thedrive system for the transducer. By computer control, the brain tumorsare located and the transducer automatically programmed for positioningsuch that the focused ultrasound beam is directed at each tumor and thedosage set to produce volume lesions.

An alternative to this position translation technique for brain tumorsis to use ultrasound to visualize the disease entity. Since brainlesioning is somewhat unique due to the CT or MRI scans and the skullfixation apparatus, the visualization technique of our co-pendingapplication may not be the most appropriate technique for ablation ofother focal disease sites.

Since some of these other disease sites may be most effectively treatedby the use of ultrasound in either a transcutaneous or intraoperativemode, there is a need to insure that the transducer components which aredesigned and the materials selected be such so as to be suitable forsteam autoclaving.

The present invention provides an ultrasound localization and therapysystem which is designed with both a visualization transducer and atherapy transducer. Those portions of the structure which must besterilized are constructed from sselected materials which are steamautoclavable.

Another concern with the treatment of disease in a transcutaneous modeby ultrasound is the physical size and shape of the probe. Since thetransducer design of the co-pending application is used external to thepatient, size and packaging considerations are not substantial. However,with the modes of examination and treatment such as transrectal,transesophogeal, etc., the probe design is critical. While the specificsof our co-pending transducer design may be used in some embodiments ofthe present invention, it will require some scaling down in size.Further, if the transducer assembly is going to be steam autoclavable,certain material changes are advisable in order to provide a finishedproduct which will withstand the high autoclaving temperatures.

In a related embodiment the concept of utilizing a visualizationtransducer in combination with a treatment transducer is disclosed fortreatment of the prostate. This particular configuration is adaptablefor use in other body cavities. The therapy treatment from within suchbody cavities by ultrasound, where ultrasound is also used for imagingof the area to be treated, has not heretofore been done.

SUMMARY OF THE INVENTION

A visualization and treatment transducer for producing lesions indiseased tissue sites according to one embodiment of the presentinvention comprises a transducer housing having a main section and adetachable enclosure, movable visualization transducer means disposedwithin the detachable enclosure, movable treatment transducer meansdisposed within the detachable enclosure, first drive means providingrotary motion to the visualization transducer means in two degrees offreedom, second drive means providing rotary motion to the treatmenttransducer means in two degrees of freedom, the visualization transducermeans and treatment transducer means having generally coaxial focal axesand the first and second drive means being operable independently ofeach other.

A transrectal or other body cavity visualization and treatmenttransducer assembly for ultrasonic visualization and treatment byproducing lesions in diseased tissue sites according to anotherembodiment of the present invention comprises a fluid-filled,flexible-walled enclosure, a movable visualization transducer disposedwithin the enclosure, a movable treatment transducer disposed within theenclosure, a reflective scanner disposed within the enclosure andaligned with the treatment transducer for changing the direction of thefocused ultrasound beam from the treatment transducer, first drive meansproviding rotary motion to the treatment transducer, second drive meansproviding linear motion to the visualization transducer, the first andsecond drive means being operable independently of each other, and thirddrive means providing rotary motion to the visualization transducer andthe treatment transducer concurrently.

One object of the present invention is to provide an improved transducerassembly including both a visualization transducer and a cooperatingtreatment transducer.

Related objects and advantages of the present invention will be apparentfrom the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic illustration of an ultrasound treatmentapparatus according to a typical embodiment of the present invention.

FIG. 2 is a side elevation, diagrammatic illustration in full section ofa transducer assembly which is suitable for use in the FIG. 1 apparatus.

FIG. 3 is a front elevation, diagrammatic illustration in full sectionof a transducer design suitable for use in the FIG. 2 transducerassembly.

FIG. 4 is a perspective, diagrammatic illustration of an ultrasonicprobe for prostate visualization and treatment.

FIG. 5 is a side elevation, diagrammatic illustration of the FIG. 4ultrasonic probe.

FIG. 6 is a lateral section view of the FIG. 4 ultrasonic probedetailing the configuration and support of a reflective scanner.

FIG. 7 is a lateral section view of the ultrasonic probe detailing thearrangement and support of the treatment transducer.

FIG. 8 is a side elevation, diagrammatic illustration in full section ofa control unit which is coupled to the FIG. 4 probe for imaging andtreatment control.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiment illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates.

Referring to FIG. 1, there is illustrated an ultrasound treatment systemgenerally in block diagram form with the patient 20 lying on anappropriate table 21 with the transducer housing 22 diaphram 23 incontact with the patient. A suitable coupling medium is used between thediaphragm and patient and the therapy transducer 24 is disposed in avolume of degassed water 25. In an intraoperative mode, sterile housing22 with its diaphragm 23 is brought into contact with sterile fluidoverlying on the internal organ or tissue directly. Guidance to thetissue or organ site is provided by ultrasound visualization element 28located inside housing 22. The relative sizes and positionalrelationships of therapy transducer 24 and visualization element 28which is an imaging transducer is best illustrated in FIG. 2.

Housing 22 is manually placed in position by the operator while beingguided by transducer 28 with the ultrasound image displayed on monitor29. Housing 22 is supported by articulating arms 30 and 31 with rotationaxes as shown by the rotary arrows. Vertical motion is shown emanatingfrom base support 32. Once the system is appropriately located fortreatment, the articulating arms and rotation axes are locked in place.From the scanning of visualization transducer 28, the treatment volumeis defined and stored in computer 35. The spatial position of thetreatment volume is also defined with respect to depth and orientationto surrounding tissues. By interacting with the tissue and organsdisplayed on monitor 36, the treatment spatial regimen is computed.Dosage parameters of sound intensity and time-on period are entered intocomputer 35.

Once the treatment regimen is established, the system automaticallyprogresses through the treatment volume by placing individual focalablative lesions. Power amplifier 37 provides the drive energy totherapy transducer 24 for each focal site under control of computer 35.Degassed water system 38 provides degassed water to the interior oftransducer housing 22 and temperature control system 39 keeps thisdegassed water at a constant temperature during the therapy procedure.The procedure can be interrupted at any time by the operator andrestarted at the last stopped position, if that is desired.

In the event the operating and control electronics are remote from thepatient, which would be the typical case, local keyboard control 42 isprovided for at-site interfacing with the computer 35. Also interfacingwith computer 35 are the ultrasound guidance and site placement system43 and the motion drive and control apparatus 44.

Referring to FIG. 2, transducer assembly 27 is illustrated. Assembly 27includes visualization transducer 28 which is a spherical ceramicpiezoelectric element mounted in a metal ring. Hollow metal rod 47attaches to this metal ring and runs through O-ring seal 48 in metalhouisng 49. Housing 49 is attached to metal housing 50 which runsthrough plate 51 and is sealed by O-ring 52. Transducer 28 ismechanically rotated (as shown by arrow) in a sector motion by rotationof rod 47 which is driven through bevel gears 55 and 56. Gear 55 isattached to rod (shaft) 47 and gear 56 is attached to drive shaft 57.Shaft 57 is driven in a rotary fashion by motor 58 which incorporates anencoder so that the angular position of transducer 28 is known. Knowingthe angular position of transducer 28 provides angular information forthe sector format (visualization) display. Electrical drivig pulses andreceiving pulses to transducer 28 go through wire lead 59 which attachesto the piezoelectric element in transducer 28 through the center hollowportion of rod 47. Transducer 28 is rotated in a plane normal to theplane of the paper from beneath transducer 22 by rotating tubularhousing 50 using attached gear 62 which meshes with gear 63 driven bystepping motor 54 which has an encoder to establish the position oftransducer 28 in this particular plane of rotary motion.

Transducer 24 is rotated on axis elements 67. This rotation isaccomplished through sprocket gear 68 driven by belt 69 which in turn isdriven by sprocket 70. Sprocket 70 is driven by shaft 71 which in turnis driven in a rotary manner by meshed bevel gears 72 and 73. Bevel gear73 is attached to and driven by shaft 74. Shaft 74 is rotatable throughO-ring seal 75 in top plate 76 which is attached to tubular housing 77.Transducers 28 and 24 are positioned so that their respective ultrasoundbeam focal axes are substantially coaxial to each other.

Tubular housing 77 is movable up and down relative to plate 51 throughO-ring seal 80. Plate 51 is rotatable in ring 81 through ring gear 82mounted to plate 51 and running entirely around the apparatus (360°circle). The parts including and below plate 51 and ring 81 aredetachable from ring 83 for autoclaving. Ring 83a is illustrated as aseparate piece but is in fact rigidly attached to ring 83. Thesecomponents remain with the support (articulating) arms during theautoclaving procedure for the parts which are detached. Similarly, gear85 is not removed for autoclaving. For autoclaving top plate 76 isremoved with housing 77 and plate 51.

After autoclaving plate 51 and ring gear 82 are inserted in ring 83 andattached by a plurality of pins 84 positioned around the periphery ofring 83a. Rotation of plate 51 is accomplished through circular ringgear 82 driven by gear 85 attached to stepping motor 86 which includesan encoder. When plate 51 rotates all attached members includingtransducer 24 rotate concurrently. Plate 76 meshes with tube 89 oninsertion of plate 51 and ring 81. When plate 76 meshes, drive shaft 74meshes with shaft 90 which is attached to stepper motor 91 whichincludes an encoder.

Electrical drive power to transducer 24 is also coupled as is pressuresystem 92 when plate 51 and ring 81 are inserted. Vertical motion oftransducer 24 is accomplished through ring 95 attached to tube 89 whichlinks with plate 76. Ring 95 can rotate freely in element 96 which isdriven up and down by gear rack 97 attached to element 96. Element 96 isconstrained by slide system 98. Gear rack 97 is driven by gear 99 whichis attached to stepper motor 100 and includes an encoder which issupported off the top surface 101 of ring 83 by member 102. Filling ofchamber 103 with degassed water 25 is accomplished through tubing member104 which is coupled through O-rings 105 to ring 81. Bath temperature in103 is maintained by coils which circulate controlled-temperature fluidintroduced through tubing 104.

Therapy transducer 24 is provided with three degrees of freedom. Theunit can be rotated about axis 106, it can be moved up and down as shownby arrow 107, and it can be rotated about axis 108. Use of these motionspermits volume lesions to be made after unit 27 is locked in position.

Referring to FIG. 3, internal details of therapy transducer 24 areillustrated in greater detail. It should be noted that this illustrationdoes not include axis elements 67 and the power cable which isdiagrammatically shown in FIG. 2 as a coiled wire connecting to thetransducer is, in the FIG. 3 illustration a coaxial cable. While FIG. 2discloses an air pressure system 92 for some of the interior spaces,FIG. 3 further includes a similar air pressure system 188 and an airpressure system 196 for controlling the silicone oil pressure for otherinterior spaces within transducer 24.

Referring to FIG. 3, transducer 24 is configured with several uniquefeatures which are provided in order for a stable acoustic output to beobtained at all preselected driving levels. These driving levels arerequired in order to produce controlled focal lesions. In order toachieve this necessary objective, it is necessary to have a stablesound-producing source such as generally circular (disc) quartz plate161 which is used in this particular embodiment. The quartz plate 161 isable to be maintained flat and parallel to generally circular,plano-concave lens 162 by the structure which will be describedhereinafter. Lens 162 is a hard anodized aluminum lens with an ellipticconcave surface for minimizing the half-intensity length of the beam atthe focus. In order to maintain flatness and parallelism of plate 161and lens 162 with a fixed spacing distance therebetween, the aluminumflat side of the lens is precisely machine flat with at least one1/8-inch diameter rod 163 machined on the surface to extend a distanceabove the lens surface equal to a 1/4 wave length in the silicone oilwhich is disposed in space 165.

In order to maintain this 1/4 wave length spacing to within plus orminus 0.0001 inches, it is required that the outer peripheral lip 162aof aluminum lens 162 provide unanodized surfaces (flat top and bottomsurfaces and outer edge surface) which rest directly in contact with theflat machined surface of housing 164 and end plate 164a. Housing 164includes an inwardly and upwardly directed lip 164b, of an annular ringconfiguration, whose underside abuts against the top surface of lip 162aand whose top surface supports plate 161. The height of this lip isprecisely machined since it is the means to fix the 1/4 wave lengthseparation between the plate 161 and lens 162. Rod 163 provides centerstabilizing for the plate due to its span between peripheral edgesupports and the pressure differential between the top and bottomsurfaces of the quartz plate. The space 165 between the plate 161 andlens 162 (the 1/4 wave length spacing) is filled with silicone oil 166which is freely exchanged through radially open channels in lip 164b. Asuitable silicone oil for this application is Dow Corning 710 fluid.Gasket 164c seals the oil in space 165.

One gold-plated and polished electrode, electrically connected to quartzplate 161, rests in direct contact with the top machined surface of lip164b and provides the electrical ground contact for the quartz plate.

In order to keep plate 161 in pressure contact with housing 164, a flat,flexible gasket 171 is firmly pressed against plate 161 through metalmember 172. In order to provide electrical contact for power to plate161 an electrode 173 fabricated of an approximate 0.001 thick soft metalfoil (gold, brass, silver) extends part-way under compression gasket171, while the remainder of gasket 171 acts as a seal for the siliconeoil. The power and ground electrodes on plate 161 do not extend to theedge of plate 161 and the silicone oil provides insulation around theedge. The foil electrode 173 is attached to metal member 172 with aseries of metal screws 174.

To provide RF power to drive quartz plate 161 a coaxial cable 179, withmetal sheath 180 drawn back and clamped under plate 181 to metal plate182, is provided. The coaxial cable has an end plug 184 which sidepressure contacts plate (metal member) 172 through a central hole. Space185 is an air space so that the quartz plate 161 is not backacoustically loaded thereby directing all its acoustic output throughthe interspace 165 and lens 162 into the fluid which is in front of lens162. To insure flatness of quartz plate 161 and parallelism with theflat surface of lens 162, the air space 185 and all other air spaces inthe transducer housing 164 are pressurized through tube 86 into element187. This air pressure holds quartz plate 161 against machined rod 163to maintain the necessary parallelism. Pressure is applied from source188.

In order to maintain a positive differential pressure in space 185relative to the pressure in interspace 165, flow communication isprovided from interspace 165 via flow access channels 189 into column190 and well 191. These areas are all silicone oil filled and inpressure equilibrium is a thin flexible diaphragm 192 which covers well191. Above diaphragm 192, the air space 193 is exhausted throughflexible tubing 194 and rigid tube 195 to the outside atmosphere.

A further feature to suppress cavitation in the oil in space 165 betweenthe quartz plate 161 and lens 162 when the system is run at the highestacoustic output power is provided by pressure system 96 providinggreater-than-atmospheric pressure to space 193. Typically this pressurewill be that which prevents any cavitation in space 165 (of the order of40-50 pounds per square inch). This pressure in space 193 is readilytransmitted through diaphragm 192 to the silicone oil in well 191 andhence through column 190 into space 165. The pressure provided by source188 is in the order of 2 pounds per square inch higher than the pressurein system 196 in order to keep plate 161 flat and held against lens 162through rod 163.

Element 199 in the transducer assembly is an insulating member to whichelement 172 is bolted by screw(s) 200. Gasket 201 keeps the silicone oilcontained in column 190 from reaching the coaxial cable 179. Metal plate182 is bolted to housing 164 around the outer periphery of plate 182.Oil is kept in column 190 and well 191 by the use of O-ring seal 203positioned between housing 164 and plate 182 and by gasket 205. Member206 is bolted and sealed to plate 182. Top metal plate 207 is bolted byscrews 203 to housing 164 and sealed thereto through O-rings 209. Metaltube 195 is sealed to element 187 through seal 210. The coaxial cable179 is water-tight and sealed to top plate 207 through member 211 andO-ring 212.

In order to accomplish the task of producing lesions of any complex sizeor shape with intense focused ultrasound it is necessary to provide forultrasound dosage conditions which produce individual focal lesions(from which the complex volume can be generated), which do notcompromise tissue outside the intended focal lesions side and permitsubsequent individual focal lesions in a contiguous manner. Whentransducer 24 is used for the treatment of brain tumors by creatinglesions in deep brain sites in both gray and white matter and abnormalbrain tissue, it is necessary to inhibit the production of microbubbleformation at the primary focal site so that there can be no vasculardispersion of such microbubbles away from the primary focal site whichmicrobubbles could initiate off primary site lesion production andhemorrhage due to ultrasound passage through microbubble comprisedtissue.

In order to accomplish this task while being able to accomplish primarysite lesions, it is necessary to derive these sound intensities as afunction of frequency which will not produce microbubbles at the primarylesion site. This requires that for a 1 MHz sound frequency (a frequencynecessary to achieve deep penetration into the human brain), the primarysite sound intensity must not exceed 300 watts per square centimeter. Atthis intensity and for lower intensities, gray and white matter lesionson a multiplicity of individual contiguous sites can be produced withoutundesirable side effects (microbubbles). As the frequency is increasedabove 1 MHz, the primary site sound intensity can be increased andproduce no microbubbles but the penetration capability in brain tissuereturns as the sound frequency is increased. At 4 MHz frequency which isthe upper frequency which can be considered for more superficial brainlesion production, the intensity which will not lead to microbubbleformation is at least 2100 watts per square centimeter. At theseintensity limits, the time-on period of sound irradiation at eachindividual site can be extended to as many seconds as is needed toablate the tissue at the focal site without microbubble formation.

In order to constrict the individual lesion sites so that the boundariesof desired volume lesions can be constrained, the transducerconfiguration used will give a half intensity length at the lesion focalregion in the order of 15 mm at 1 MHz operating frequency. This lengthof half intensity is consistent with the necessity of constraininglesions in the human brain so that the extending of individual lesionsinto white matter (white matter is more sensitive than gray matter) canalso be constrained.

Still referring to FIG. 3, in order to make the transducer assembly 27capable of being steam autoclaved, gasket 171 needs to be made fromfluorosilicone in order to take the high autoclave temperature andresist the uptake of the silicone oil which is used within the assembly.A suitable silicone oil for this application is Dow Corning 710 fluidwhich has the necessary high temperature resistance. All gaskets incontact with the Dow Corning 710 fluid must be made of fluorosilicone.All other O-rings and gaskets not in contact with the Dow Corning 710fluid can be made of silicone. Insulator 199 must be a high-temperatureplastic, such as, for example, General Electric's Ultem. Coaxial cable179 must also include high-temperature materials such as Tefloninsulation. The volume expansion chamber (well) 191 requires afluorosilicone membrane 192 which must be capable of taking thevolumetric expansion of the silicone oil during the autoclavingprocedure. The system design requires that all differential expansionsbe accounted for when the steam autoclaving is performed.

As previously pointed out, one of the primary concerns withtranscutaneous and intraoperative modes of ultrasound treatment is theneed to design the transducer assembly so that those portions that needto be autoclaved can be steam autoclaved. Recognizing that the entiretyof the assembly will not be contaminated by use in the prior treatmentprocedure, only selected components need to be autoclaved and these aredetachable as previously described. Another concern is the ability tovisualize the area for treatment. In order to guide and manuever thetherapy (treatment) transducer to the appropriate ablation sites withinthe body, some visualization means must be employed. In the disclosedembodiment of FIGS. 1-3, the visualization means is the visualizationtransducer 28. Yet another concern with a transcutaneous mode oftreatment is the size and shape of the probe (transducer assembly andhousing). Transcutaneous modes may include transrectal ortransesophogeal, for example.

Localization and treatment (tissue destruction) of the prostate by wayof a transrectal route requires both the ability to localize thetreatment volume and then to apply the treatment regimen in thatidentified volume. One configuration to accomplish this particular taskis described in FIGS. 4-8.

In the FIG. 4 embodiment, ultrasound probe 240 is illustrated asinserted into the rectum and positioned for visualization and treatmentof the prostate 241. Also illustrated and positioned in FIG. 4 are theurinary bladder 242 and rectum 243. Diagrammatically illustrated is across-section area of the tapered stem of probe 240 in order to show theentry diameter 244. The probe is inserted by way of the rectal entryregion 245.

Referring to FIG. 5, the internal features and components of probe 240are diagrammatically illustrated. In answer to concerns previouslymentioned, probe 240 includes a focused transducer 248 for deliveringthe therapy (ablation) which is supported by and movable relative to armelements 249 positioned within flexible envelope 250. Envelope 250 isfilled with water so as to expand to contact the rectal wall, but byremoval of some water and some rotation of transducer 248 and mirror256, the size is reduced to make entry easier. Arm elements are curvedso that when the unit is in the rectum, the diameter at the entry of theprobe is smaller than the remainder.

Visualization element 253 includes in its interior space transducer 254which is operable to generate ultrasound imaging beam 255 in thedirection of the prostate. Transducer 248 is movable in a rotary mannerrelative to elements 249 and has a focused beam directed at circular(disc) mirror 256 which is adapted to bend and redirect beam 257 towardthe desired region of the prostate. The movement of transducer 248relative to mirror 256 is used to affect the depth of the beam (focusedspot) into the prostate. Since the transducer beam has a fixed focus,the less of the beam length used between the transducer and mirror, thelonger the beam length reflected from the mirror. Transducer 248 is alsomovable linearly with mirror 256 along the longitudinal axis of probe240. The entire probe portion is rotatable by external means asillustrated in FIG. 8.

Referring to FIG. 6, the support of mirror 256 by arm elements 249 andrelated components is illustrated in greater detail. As previouslydescribed, elements 249 which support transducer 248 and by means ofrotary and sliding extensions 260 also support mirror 256. Arm elements249 are thin-walled, hollow, flexible tubes open at their proximal endfor the exiting of elements 262 and 263 (FIG. 7) and bands 273 and 274(FIG. 7). Extensions 260 rigidly attach to mirror 256 and extend throughslot 267 so that linear movement of the mirror relative to elements 249can be affected. Extensions 260 fit within elements 262 for rotarymotion and elements 262 travel in top and bottom tracks 268 formed aspart of the interior wall surface of element 249. Referring to FIG. 7,the extension of elements 249 and their coupling to transducer 248 isillustrated. Both FIGS. 6 and 7 should be regarded as lateral sectionslooking along the longitudinal axis of the ultrasonic probe 240 with themirror and transducer oriented so as to reveal their full disc(circular) configuration. The structure of FIG. 7 is virtually the sameas FIG. 6 with one main difference. The rotational and linear travellinkage made up of elements 263, 270, 272 and 274 for transducer 248 isoutward, relative to element 249, from elements 262, 269, 271 and 273for the mirror. This allows the linear travel of the mirror to beseparately controlled as well as the rotation relative to element 263,without interference between the transducer and mirror and theirlinkages.

Referring now additionally to FIG. 8, control unit 261 which attaches tothe reduced diameter end of probe 240 is illustrated. The linearmovements on both transducer 248 and mirror 256 are accomplished by thelinear translation of elements 262 and 263 which are flexible strips orbands so that they are able to accommodate the configurational bend inarm elements 249. Elements 262 and 263 are coupled to linear actuatorsand encoders, all of which are represented by block 264 through couplers265 and 266. This arrangement permits coordinate linear translation ofthe therapy transducer and reflective mirror with respect to thevisualization element 253 and the beam 255 generated by transducer 254.Rotation of focused transducer 248 and reflective mirror 256 isaccomplished by crank arms 269 and 270. The crank arms with pins 271 and272 are in turn driven by bands 273 and 274. These bands are connectedto the linear actuators and encoders represented by block 264 by way ofcouplers 275 and 276. This particular arrangement permits thecoordination of linear translation and/or relative translations torotate the focused transducer 248 and reflective mirror 256.

On insertion of ultrasonic probe 240 into the rectal area, the focusedtransducer and reflective mirror are rotated so as to reduce as much aspossible the overall outside contour of the probe upon entry into thepatient. The mirror may be rotated on axis, i.e., relative to elements249 in order to gain additional space within the probe for movement ofthe visualization transducer 254. Except for these two instances ofmirror rotation, it remains rotationally fixed.

When visualizing the prostate elements, the focused transducer andreflective mirror are translated as shown so that free visualization ofthe prostate can be accomplished and then the transducer 248 andreflective mirror 256 positioned in order to place beam 257 at thepositions delineated by beam 255. These position determinations are madethrough encoder determinations arrived at by computer computations.Visualization element 253 is linearly translated and encoded by rack279, pinion 280, shaft 281, and drive motor with encoder 282.

In order to provide rotary motion in the rectum, the entire systemincluding control unit 261 can be rotated through ring gear 285 drivenby pinion or drive gear 286 and motor encoder 287.

Filling (and emptying) of the unit with degassed water is done throughtubes 288 and 299 so that the entire system is water-filled and meansfor removing trapped air bubbles provided. This arrangement avoidssliding seals at the juncture between the insertable elements and theexterior elements. Flexible envelope 250 is attached to control unit 261by slipping band 290 over the outer surface of envelope 250.

All electrical leads, some of which are shown diagrammatically, passthrough water-tight seals in control unit 261. Electrical power to thefocused transducer 248 is provided by an electrical lead which travelsalong arm element 249.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

What is claimed is:
 1. An ultrasound imaging and treatment device foruse in the treatment of a patient by means of ultrasound energy, saiddevice comprising:an enclosed transducer housing designed and arrangedto be positionable onto the patient; a visualization transducer disposedwithin said housing and movable relative to said housing; a treatmenttransducer disposed within said housing and movable relative to saidhousing; first drive means for imparting linear motion to said treatmenttransducer relative to said housing; second drive means for impartingrotary motion to said treatment transducer relative to said housing; andthird drive means for imparting rotary sector motion to saidvisualization transducer relative to said housing.
 2. The device ofclaim 1 wherein said first drive means includes a rack and piniongearing arrangement.
 3. The device of claim 1 wherein said second drivemeans includes a ring and pinion gearing arrangement.
 4. The device ofclaim 1 wherein said third drive means includes a motor-driven bevelgear arrangement.
 5. The device of claim 4 wherein said second drivemeans includes a ring and pinion gearing arrangement.
 6. The device ofclaim 5 wherein said first drive means includes a rack and piniongearing arrangement.
 7. The device of claim 1 which further includesfourth drive means for imparting a second type of rotary motion to saidtreatment transducer.
 8. The device of claim 1 wherein said treatmenttransducer and said visualization transducer each have a focal axis forthe ultrasound which is emitted and each are positionable such thattheir respective focal axes are coaxial with each other.
 9. The deviceof claim 1 wherein said enclosed transducer housing is configured intotwo portions, one portion being fluid-filled and detachable from theother portion.
 10. The device of claim 9 wherein said treatmenttransducer and said visualization transducer are disposed entirelywithin said fluid-filled, detachable portion.
 11. An ultrasound imagingand treatment device for use in the examination and treatment of theprostate by means of ultrasound energy, said device comprising:anenclosed, fluid-filled, flexible-walled probe which is sized and shapedso as to be insertable into a patient's rectum; a visualizationtransducer disposed within said probe and movable relative to saidprobe; a treatment transducer designed to generate an ultrasound beamand disposed within said probe and movable relative to said probe; firstdrive means providing rotary motion to said treatment transducerrelative to said probe; second drive means providing linear motion tosaid visualization transducer relative to said probe; and said first andsecond drive means being operable independently of each other.
 12. Thedevice of claim 11 which further includes reflective scanning meansdisposed within said probe and aligned with said treatment transducerfor changing the direction of the ultrasound beam emitted from saidtreatment transducer.
 13. The device of claim 12 which further includesthird drive means providing rotary motion to said visualizationtransducer and to said treatment transducer concurrently.
 14. The deviceof claim 13 wherein said second drive means includes a geared drivearrangement.
 15. The device of claim 11 which further includes thirddrive means providing rotary motion to said visualization transducer andto said treatment transducer concurrently.